Zeus, Poseidon, and Hades were the three sons of Cronos. When Cronos retired, the boys divided the world up between them. Zeus took the sky, Poseidon took the sea, and Hades ruled under the earth, the home of the dead. At first, it was great fun. But things had been just a bit slow lately.
Zeus flew down to earth and looked around for something to do. He spotted two men walking along a lane. Zeus cast his voice to make it sound like somebody else was speaking. He was very good at that.
Hoping to hide himself from the eagle eye of his jealous wife, Zeus covered the world with some really thick clouds. Then he flew down to Io. But Hera was not stupid. The thick coat of clouds made her suspicious immediately.
Quickly, Zeus changed Io into a cow. When Hera landed, all she found was an innocent looking Zeus standing next to a little white cow.
Zeus arranged for Io to be rescued and set free. He sent his son Apollo to sing the guard asleep. When the guard closed his eyes, Io ran away. When Hera heard about it, she sent a gadfly after Io. A gadfly is a fly that bites. "Moo moo," Io screamed, when the gadfly found her. Io swam across a sea, hoping the gadfly would drown on the trip. No such luck, although Hera did name the sea between Greece and Rome after Io. Perhaps you've heard of it - the Ionian Sea? No matter.
It was then that Hera decided that Io had suffered enough. First, she made Zeus promise that he would never see Io again. Then she changed Io back into human form, and left her in Egypt. Egypt was a dismal place for a river nymph. There are crocodiles in the Nile. Back in Greece, Zeus gave a big sigh. Surely there was something he could do ....